[whatwg] Form element invalid message
Jukka K. Korpela
jkorpela at cs.tut.fi
Thu Jul 28 03:25:40 PDT 2011
28.07.2011 12:16, Scott González wrote:
> I agree that it's extremely important to be able to define error
> messages per error condition, but it's not necessary to code all data
> checking in JavaScript to achieve that today.
It's not, but if you cannot set the error messages in HTML, what's the
point? Doing everything in JavaScript is simpler, especially because you
should anyway duplicate the checks - for example, using JavaScript to
get the pattern attribute value and run the check in it, to deal with
the many situations where the user has JavaScript enabled and the
browser does not support the pattern attribute (but still includes its
value into the DOM).
> You can simply code the
> error message by letting the browser do the validation, then using the
> validity flags to set your own message with setCustomValidity.
Pardon? You would let the browser run the checks specified in HTML, then
check the flags and turn an error to a custom error for which you can
set the error message. This sounds like more complicated than doing it
all in JavaScript, where you can directly do whatever error processing
needs to be done. To make the HTML way a feasible option, the spec
should define an easy way to set the error message(s) directly.
> I have a feeling you'll still end up with a few
> shortcomings because you won't have control over the order in which the
> checks are done, so you won't be able to specify which error message to
> show when there are multiple errors.
Yes that would be a problem too, but a tolerable one. Besides, I guess
the spec could say that the checks are carried out in the order in which
the attributes are specified (though this admittedly deviates from the
DOM-centric approach), and it could have yet another Boolean attribute
that specifies whether all checks are carried out or the first failure
aborts the processing. But more realistically, and more logically
DOM-wise, the spec could simply define the order (e.g., required,
maxlength, pattern) and specify that when a check fails, an error
message is issued and further processing is suppressed.
--
Yucca, http://www.cs.tut.fi/~jkorpela/
More information about the whatwg
mailing list